1. Field of the Invention
The present disclosure relates to an elastic wave resonator used in a filter or a duplexer of a mobile communication device or the like.
2. Description of the Related Art
In recent years, there has been an increasing demand for a high performance elastic wave device having excellent temperature characteristics. In order to achieve such an elastic wave device, studies have been made for use of an elastic wave resonator that has an improved temperature characteristic by using a piezoelectric substrate of lithium niobate, and by providing a silicon oxide film over an inter-digital transducer (IDT) electrode. Such an elastic wave device uses, for general purposes, a technique of apodization weighting in electrode fingers of the IDT electrode in order to reduce or eliminate spurious signals in a higher-order transverse mode. As a prior art literature relating to the present disclosure, Patent Literature (PTL) 1 has been known.